Interpretive Summary: The Oriental fruit fly is a wide-spread pest of fruit and vegetable agriculture throughout the Pacific Islands and South East Asia. One of the approaches to managing this important pest is use of a sterile insect technique (SIT). SIT is largely dependent on mass rearing of the insects. Therefore, it is very important to understand the nutrition part of diet. We have found wheat germ oil (WGO) in larval diets influences gene expression. We tried to identify which fatty acid contained in WGO play the major role in influencing gene expression. We conclude that changes in tissue C18 poly unsaturated fatty acids in heavily involved.

Technical Abstract:
Sterile Insect Technique programs have been developed for management of several tephritid fruit fly pests. These programs are based on continous production of adult fruit flies. The high expense of mass-rearing oriental fruit flies drive research to improve the cost effectiveness of rearing programs. One recent improvement for mass rearing oriental fruit flies involves adding wheat germ oil (WGO) to the larval culture medium which improved several parameters of biological performance. The performance enhancing influence of WGO is due to the presence of polyunsaturated fatty acids (PUFAs), some of which are nutritionally essential for many insect species. We considered the issue of whether WGO supplementation of the larval culture medium influences the fatty acid make up of adult tissues. We report that WGO supplementation led to substantial increases in adult tissue C18 PUFAs. Unlike the outcomes of unrelated nutritional studies on moths, the PUFA components of WGO did not improve adult fruit fly performance. Taken with recent publications reporting that WGO in larval diets infulences gene expression, we concude that dietary WGO improved bilogical performance of adults through changes in tissue C18 PUFAs and gene expression.